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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Tribologists and Lubrication Engineers
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Journal DOI :
The Korean Society of Tribologists and Lubrication Engineers
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Volume & Issues
Volume 25, Issue 6 - Dec 2009
Volume 25, Issue 5 - Oct 2009
Volume 25, Issue 4 - Aug 2009
Volume 25, Issue 3 - Jun 2009
Volume 25, Issue 2 - Apr 2009
Volume 25, Issue 1 - Feb 2009
Selecting the target year
Study on the Frictional Characteristics of Micro-particles for Tribological Application
Sung, In-Ha ; Han, Hung-Gu ; Kong, Ho-Sung ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 2, 2009, Pages 81~85
Interests in micro/nano-particles have been greatly increasing due to their wide applications in various fields such as environmental and medical sciences as well as engineering. In order to obtain a fundamental understanding of the tribological characteristics at particle-surface contact interface, frictional behaviors according to load/pressure and materials were obtained by using atomic force microscope(AFM) cantilevers with different stiffnesses and tips. Lateral contact stiffnesses were observed in various tip-surface contact situations. Experimental results show that stick-slip friction behavior occurs even when the colloidal probes with a particle of a few micrometers in diameter, which have a relatively large contact area and lack a well-shaped apex, were used. This indicates that atomic stick-slip friction may be a more common phenomenon than it is currently thought to be. Also, experimental results were investigated by considering the competition between the stiffness of the interatomic potential across the interface and the elastic stiffnesses of the contacting materials and the force sensor itself.
Effect of Temperature on the Micro-scale Adhesion Behavior of Thermoplastic Polymer Film
Kim, Kwang-Seop ; Heo, Jung-Chul ; Kim, Kyung-Woong ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 2, 2009, Pages 86~95
Adhesion tests were carried out in order to investigate the effect of temperature on the adhesion behavior between a PMMA film and a fused silica lens in the micro scale. For the tests, a microtribometer system was specially designed and constructed. The pull-off forces on the PMMA film were measured under atmospheric condition as the temperature of the PMMA film was increased from 300 K to 443 K and decreased to 300 K. The contact area between the PMMA film and the lens was observed during the test. The adhesion behavior was changed with the change of the PMMA surface state as the temperature increased. In glassy state below 363 K, the pull-off force did not change with the increase of temperature. In rubbery state from 383 K to 413 K, the pull-off force increased greatly as the temperature increased. In addition, the area of contact was enlarged. In viscous state above 423 K, the fingering instability was observed in the area of contact when the PMMA film contacted with the lens. It was also found that the adhesion behavior can be varied with the thermal history of the PMMA film. The residual solvent in the PMMA film could emerge to the PMMA surface due to the heating and reduced the pull-off force.
Leakage Characteristic of Angled-Circumferential-Groove-Pump Seal with CFD Analysis
Choi, Bok-Sung ; Ha, Tae-Woong ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 2, 2009, Pages 96~101
In order to improve leakage characteristic, angled-circumferential-groove pump seal is suggested. CFD analysis using FLUENT has been performed to predict leakage and determine an optimum slanted-groove angle
which yields the best leakage reduction. The optimum value of
and depends on the pressure difference of seal and number of grooves for the same groove geometry. The maximum leakage reduction ratio increases as increasing the pressure difference of angled-circumferential-groove pump seal with the optimum value of
A Study on Thermal Deformation Volume of Motorcycle Brake Disk using Regression Analysis
Ryu, Mi-Ra ; Byoun, Sang-Min ; Park, Heung-Sik ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 2, 2009, Pages 102~107
The thermal deformation volume of motorcycle break disk was studied using a disk-on-pad type friction tester. Thermal deformation volume of motorcycle break disk have an effect on the frictional factor such as applied load, sliding speed, sliding distance and number of ventilated disk hole. However, it is difficult to know the mutual relation of these factors on thermal deformation volume. In this study, the thermal deformation volume with ANSYS workbench are obtained by application of temperature from mechanical test. From this study, the result was shown that the motorcycle break disk with ventilated hole 3 have the most excellent thermal deformation characteristics. The regression equation with frictional factors which have a trust rate of 95% for prediction of thermal deformation volume of motorcycle break disk was composed.
Performance Test of Double-Bumped Air Foil Bearings
Kim, Young-Cheol ; Lee, Dong-Hyun ; Kim, Kyung-Woong ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 2, 2009, Pages 108~113
This paper presents a experimental results for the performance evaluation of a double-bumped air foil bearing. The test results of a double-bumped AFB is compared with a single-bumped AFB at a heavily-loaded condition. The diameter of the test bearing is 50 mm, and the axial length is 50 mm. Nominal clearance of the single-bumped AFB is evaluated as
, and that of the double-bumped AFB is as
. The test of the AFBs are demonstrated at 3 test mode; the load variation mode, the speed variation mode, and start-stop mode. The single-bumped AFB demonstrated a upward load-carrying capacity of 95 N and a downward load-carrying capacity of 130 N at 20,000 rpm. The double-bumped AFB demonstrated a upward load-carrying capacity of 170 N and a downward load-carrying capacity of 170 N at 20,000 rpm. The single-bumped AFB demonstrated a downward lift-off speed of 16,300 rpm at 105 N. The double-bumped AFB demonstrated a downward lift-off speed of 15,400 rpm at 105 N. The start-stop test of the AFBs assure 5,000 cycle endurance life. The test results are compared with the theoretical calculation results. The test and theorectical results show thata double-bump air foil bearing provides a higher load-carrying capacity, stiffness and damping than a single-bump air foil bearing in a heavily-loaded condition.
A study on estimating of contact pressure and surface shape change due to fretting wear
Kim, Jong-Sung ; Lee, Sang-Don ; Cho, Yong-Joo ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 2, 2009, Pages 114~119
Fretting occurs wherever short amplitude reciprocating sliding between contacting surfaces is sustained for a large number of cycles. The fundamental characteristic of fretting is the very small amplitude of sliding and combination of different wear mechanism. Predicting wear is important to enhance reliability of the parts. The objective of this paper is to predict fretting wear by using a contact analysis considering wear process. This construction will give us important information to know a property of fretting wear.
Wear Characteristics of Rubber-Seal for Inflow of Dust Particle in Automobile Chassis System PART I : Analysis of Dust Particle for Inflow in Automobile Chassis System
Lee, Young-Ze ; Chung, Soon-Oh ; Won, Tae-Yeong ; Kim, Gi-Hoon ; Kim, Dae-Sung ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 2, 2009, Pages 120~124
In automobile chassis system, several environmental factors weaken durability of automobile's components. The environmental factors are temperature, humidity, intensity of radiation and dust particle inflow. Especially, dust particle inflow leads to increase in friction and wear of automobile's components. The wear of automobile's component leads to increase in noise and exerts a bad influence on life of components. In this study, dust particles were investigated for study on the influence of dust particle inflow. Dust particles are collected on urban area, rural area and highway in China. The size of dust particle is analyzed using the image plus program, and the element of dust particle is analyzed using the SEM and EDX. The elements of dust particle are
. The other elements(Na, Ca, Cl etc..) are detected on urban area and highway.
The study of lubricity for various biodiesel using HFRR
Lim, Young-Kwan ; Kim, Dong-Kil ; Yim, Eui-Soon ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 2, 2009, Pages 125~131
Biodiesel produced from triglyceride which is main component of animal fats and vegetable oils by methanolysis was known for excellent lubricity. In this study, the lubricity of 12 kinds of biodiesel come from vegetable oils were analyzed using HFRR(High frequency reciprocating rig). The biodiesel synthesized from soybean oil has best lubricity by
of wear scar in HFRR and used fried oil's biodiesel has slightly low lubricity by
. Also we have found that the lubricity of diesel was improved when mixing ratio of soybean biodiesel was increased in base diesel.